Trading Post on the Arkansas River Near the Rockies in 1833?

There was no trading post built on the Arkansas River near the Rocky Mountains in 1833. The Arkansas River flows through the central United States—Colorado, Kansas, Oklahoma, Arkansas—far from the main Rocky Mountain chain. While fur trade posts existed in the Rockies (e.g., Fort Laramie, Bent's Fort), none were on the Arkansas River in that vicinity at that time. The question may confuse the Arkansas with the South Platte or other mountain streams.